Laboratoire de Physique Théorique et Hautes Energieshttps://www.lpthe.jussieu.fr/
frSPIP - www.spip.netLaboratoire de Physique Théorique et Hautes Energieshttp://www.lpthe.jussieu.fr/spip/IMG/siteon0.png?1476645635https://www.lpthe.jussieu.fr/
8029411-13 Avril 2018, "Rencontre de Physique des Particules"http://www.lpthe.jussieu.fr/spip/spip.php?article250
http://www.lpthe.jussieu.fr/spip/spip.php?article2502018-03-07T18:20:45Ztext/htmlfrPietro SlavichActualité du laboratoire
<p>Voir ici l'annonce complet.</p>
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<a href="http://www.lpthe.jussieu.fr/spip/spip.php?rubrique15" rel="directory">Actualité du laboratoire</a>
<div class='rss_texte'><p>Voir <a href="https://indico.cern.ch/event/703829/overview" class='spip_out' rel='external'>ici</a> l'annonce complet.</p></div>
Propositions de stage ou thèse au LPTHEhttp://www.lpthe.jussieu.fr/spip/spip.php?article223
http://www.lpthe.jussieu.fr/spip/spip.php?article2232017-12-01T15:50:21Ztext/htmlfrPietro SlavichActualité du laboratoire
<p>Voir la version anglaise.</p>
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<a href="http://www.lpthe.jussieu.fr/spip/spip.php?rubrique15" rel="directory">Actualité du laboratoire</a>
<div class='rss_texte'><p>Voir la <a href="http://www.lpthe.jussieu.fr/spip/spip.php?article223&lang=en" class='spip_out'>version anglaise</a>.</p></div>
Matière Condensée et Physique Statistiquehttp://www.lpthe.jussieu.fr/spip/spip.php?article63
http://www.lpthe.jussieu.fr/spip/spip.php?article632012-11-07T18:01:14Ztext/htmlfrDamien BrémontPhysique Statistique et Matière Condensée
<p>En construction, voir version anglaise.</p>
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<a href="http://www.lpthe.jussieu.fr/spip/spip.php?rubrique12" rel="directory">Physique Statistique et Matière Condensée</a>
<div class='rss_texte'><p>En construction, voir <a href="http://www.lpthe.jussieu.fr/spip/spip.php?article14&lang=en" class='spip_out'>version anglaise</a>.</p></div>
Quantum out of equilibrium dynamicshttp://www.lpthe.jussieu.fr/spip/spip.php?article213
http://www.lpthe.jussieu.fr/spip/spip.php?article2132012-11-06T22:38:38Ztext/htmlfrDamien BrémontPhysique Statistique et Matière Condensée
<p>Besides their experimental relevance and possible technological application, the behavior of quantum systems out of equilibrium is a topic of fundamental interest, the understanding of which is still at an early stage. Some techniques of classical dissipative systems have been generalized to the quantum case but important questions remain to be answered such as which would be the meaning of the effective temperature appearing in fluctuation-dissipation relations out of equilibrium. The (...)</p>
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<a href="http://www.lpthe.jussieu.fr/spip/spip.php?rubrique12" rel="directory">Physique Statistique et Matière Condensée</a>
<div class='rss_texte'><p>Besides their experimental relevance and possible technological application, <br class='autobr' />
the behavior of quantum systems out of equilibrium is a topic of fundamental<br class='autobr' />
interest, the understanding of which is still at an early stage.<br class='autobr' />
Some techniques of classical dissipative systems have been generalized to the quantum case but important questions remain to be answered such as which would be the meaning of the effective temperature appearing in fluctuation-dissipation relations out of equilibrium. <br class='autobr' />
The time-dependent (second and higher order) correlation functions and the (linear and non-linear) responses of systems evolving close to equilibrium satisfy a number of model independent relations. In classical dynamics these fluctuation-dissipation theorems are Ward identities of a symmetry of the, generically non-Markovian, dynamic generating functional. The quantum version is work in progress. We studied the effect of a drive, realized in the form of the coupling to <br class='autobr' />
two fermion reservoirs at different chemical potentials, on the phase transition and coarsening dynamics of coupled quantum rotors. In experimental systems the coupling to an environment is usually unavoidable. We studied the effect of a non-Ohmic classical bath on the critical (Langevin) dynamics of the classical —phi-4, O(N) model in the large N limit by using the dynamic renormalization-group. We showed that although the critical temperature and critical dimensions <br class='autobr' />
are not altered by the bath, the dynamic critical exponent is, for sufficiently sub-Ohmic baths. As a step towards understanding impurity motion in one dimensional ultra cold quantum liquids, we derived the non equilibrium correlation function of a quantum Brownian particle with general Gaussian<br class='autobr' />
non-factorizing initial conditions. We studied the possible emergence of thermal behavior long after the quench of a closed quantum system by studying fluctuation-dissipation relations in which parameters replace the equilibrium temperature. We analyzed these relations in the stationary regime after a quench in the transverse field of the quantum Ising chain. <br class='autobr' />
The lack of thermalization to a Gibbs ensemble became apparent with this approach.</p></div>
Dynamics through phase transitionshttp://www.lpthe.jussieu.fr/spip/spip.php?article212
http://www.lpthe.jussieu.fr/spip/spip.php?article2122012-11-06T22:33:51Ztext/htmlfrDamien BrémontPhysique Statistique et Matière Condensée
<p>Sub-critical coarsening is the process whereby a macroscopic system in contact with an equilibrium reservoir orders after a rapid change in a parameter that takes it from a disordered phase into an ordered one in its equilibrium phase diagram. Closely related is critical coarsening, the process whereby a critical state is approached by quenching a disordered system right to the critical point. One of our goals is to characterize the geometry of coarsening phenomena in distribution. We (...)</p>
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<a href="http://www.lpthe.jussieu.fr/spip/spip.php?rubrique12" rel="directory">Physique Statistique et Matière Condensée</a>
<div class='rss_texte'><p>Sub-critical coarsening is the process whereby a macroscopic system in contact with an equilibrium reservoir orders after a rapid change in a parameter that takes it from a disordered phase into an ordered one in its equilibrium phase diagram. Closely related is critical coarsening, the process whereby a critical state is approached by quenching a disordered system right to the critical point. <br class='autobr' />
One of our goals is to characterize the geometry of coarsening phenomena in distribution. We studied analytically the statistical and geometric properties of ordered structures in planar curvature driven coarsening. The results provide the first analytic proof of dynamic scaling in more than one dimension for a finite dimensional order parameter. We studied numerically 2d phase separation, domain growth <br class='autobr' />
in the random bond ferromagnetic Ising model and the Potts model. Experiments in a liquid crystal -film confirmed our predictions and demonstrated that monitoring the time-evolution of structures can be a very efficient way to determine the dynamic universality class. More recently, we analyzed these same questions after a quench to a critical point. We studied the relaxation of the 2d kinetically constrained spiral model. We showed that any unblocked state de-correlates in -finite times in the full phase diagram and we proved that the dynamics occur via coarsening of vacancy lines.<br class='autobr' />
Quenches at very slow rates attracted a lot of attention in the cosmology and the condensed matter communities. A proposal for the cooling-rate dependence is given by the Kibble-Zurek (KZ) mechanism. We revisited these ideas in phase ordering systems across a second order phase transition and we revealed the limitations of the KZ mechanism. Next, we extended the analysis to the KT transition in the 2d XY model.</p></div>
Fluctuations in glassy systemshttp://www.lpthe.jussieu.fr/spip/spip.php?article211
http://www.lpthe.jussieu.fr/spip/spip.php?article2112012-11-06T22:28:54Ztext/htmlfrDamien BrémontPhysique Statistique et Matière Condensée
<p>Glassy dynamics occur out of equilibrium with special properties such as physical aging, memory effects and dynamic heterogeneities, that is to say, regions of particles rearranging cooperatively at the nanometer scale, at very different rates compared with the bulk. Such features have been observed in a wide variety of materials including vortex matter in high-Tc superconductors. The symmetry that captures the universal fluctuating aging dynamics of glassy systems should be the (...)</p>
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<a href="http://www.lpthe.jussieu.fr/spip/spip.php?rubrique12" rel="directory">Physique Statistique et Matière Condensée</a>
<div class='rss_texte'><p>Glassy dynamics occur out of equilibrium with special properties such as physical aging, memory effects and dynamic heterogeneities, that is to say, regions of particles rearranging cooperatively at the nanometer scale, at very different rates compared with the bulk. Such features have been observed in a wide variety of<br class='autobr' />
materials including vortex matter in high-Tc superconductors. <br class='autobr' />
The symmetry that captures the universal fluctuating aging dynamics of glassy systems should be the invariance of an effective dynamical action under uniform reparametrizations of the time-scales.<br class='autobr' />
This scenario was put to the test with Monte Carlo simulations of the 3d<br class='autobr' />
Edwards-Anderson spin-glass, the 3d random field Ising model, and confocal <br class='autobr' />
microscopy data on dense (super-cooled liquid and glassy) colloidal suspensions. <br class='autobr' />
We constructed restricted averages to obtain objects with a better statistics than the<br class='autobr' />
completely fluctuating ones. The outcome of these studies is that while truly glassy systems conform to the consequences of the hypothesis, simple coarsening does not with time-reparametrization invariance being reduced to time rescaling at the heart of the difference. This result suggests that the fluctuations are intimately related to the global effective temperature.<br class='autobr' />
A directed elastic manifold in random media is a system with many glassy aspects due to the competition between elasticity and disorder. The study of the Edwards-Wilkinson and a disordered elastic line, confirmed the growth of a coherence length that controls the scaling properties of averaged observables. A set of regimes going from normal diffusive aging to saturation -a la Family-Vicsek for finite-length lines passing through activated aging have been exhibited. The fluctuations of two-time quantities behave has also been analyzed.<br class='autobr' />
As a first step towards a successful field theory of Brownian particles in interaction, we studied exactly the Brownian gas. Even though the particles do not interact, the field theory contains an interaction term that enforce the constraint of a strictly positive density field. In this paper we determined non-perturbatively the Poissonian nature of the ground state.</p></div>
Electronic systems in low dimensions.http://www.lpthe.jussieu.fr/spip/spip.php?article210
http://www.lpthe.jussieu.fr/spip/spip.php?article2102012-11-06T22:25:02Ztext/htmlfrDamien BrémontPhysique Statistique et Matière Condensée
<p>1) One-dimensional interacting electrons. An important class of multi-loop diagrams (beyond the Dzyaloshinskii-Larkin theorem) has been related to the equilibration of one-dimensional interacting electrons. The remarkable result is the derivation of a T3-law for the energy relaxation of thermal carriers.<br class='autobr' />
2) Reduced quantum electrodynamics (RQED). We have computed radiative corrections, up to 2 loop, for a general RQED. Remarkable results have been found : when the gauge -field is (...)</p>
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<a href="http://www.lpthe.jussieu.fr/spip/spip.php?rubrique12" rel="directory">Physique Statistique et Matière Condensée</a>
<div class='rss_texte'><p>1) One-dimensional interacting electrons. An important class of multi-loop diagrams (beyond the Dzyaloshinskii-Larkin theorem) has been related to the equilibration of one-dimensional interacting electrons. The remarkable result is the derivation of a T3-law for the energy relaxation of thermal carriers.</p> <p>2) Reduced quantum electrodynamics (RQED). We have computed radiative corrections, up to 2 loop, for a general RQED. Remarkable results have been found : when the gauge -field is four-dimensional, its beta function is zero (as in the Luttinger liquid case). Moreover, the 2-loop interaction correction numerical constant to the polarization operator (conductivity) has been computed. It's smallness may be an indication that interaction correction are (still) diff-cult to observe experimentally for (non-relativistic) graphene.</p> <p>3) Skyrmion lattices for integer quantum Hall systems. We have studied quantum Hall ferromagnets with topologically charged spin textures in the presence of internal degrees of freedom such as spin, valley, or layer indices, so that the system is parametrised by a d-component complex spinor field.<br class='autobr' />
In particular we have computed analytically the complete low-lying excitation spectrum, which separates into d^2-1 gapless acoustic magnetic modes and a magnetophonon.</p></div>
Publications du LPTHE sur INSPIREhttp://www.lpthe.jussieu.fr/spip/spip.php?article189
http://www.lpthe.jussieu.fr/spip/spip.php?article1892011-10-06T15:58:22Ztext/htmlfrDamien BrémontPublications du LPTHE sur INSPIRE
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<a href="http://www.lpthe.jussieu.fr/spip/spip.php?rubrique41" rel="directory">Publications du LPTHE sur INSPIRE</a>
partie dehttp://www.lpthe.jussieu.fr/spip/spip.php?article6
http://www.lpthe.jussieu.fr/spip/spip.php?article62008-04-24T15:59:22Ztext/htmlfrDamien BrémontA noter
<p>Le laboratoire fait partie<br class='autobr' />
de l'ILP <br class='autobr' /> (Institut Lagrange de Paris)<br class='autobr' /> <br class='autobr' />
Le laboratoire fait partie<br class='autobr' />
de la FRIF <br class='autobr' /> (Fédération de Recherche Interactions Fondamentales)</p>
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<a href="http://www.lpthe.jussieu.fr/spip/spip.php?rubrique16" rel="directory">A noter</a>
<div class='rss_texte'><p><span class='spip_document_35 spip_documents spip_documents_center'>
<img src='http://www.lpthe.jussieu.fr/spip/local/cache-vignettes/L100xH62/logo-ilp-3-2-c169a.jpg' width='100' height='62' alt="" /></span></p> <p>Le laboratoire fait partie</p> <p>de l'<a href="http://ilp.upmc.fr/" class='spip_out' rel='external'>ILP</a> <br class='autobr' />
(Institut Lagrange de Paris)</p> <p><html></p> <p> </p> <p></htlm></p> <p><span class='spip_document_32 spip_documents spip_documents_center'>
<img src='http://www.lpthe.jussieu.fr/spip/local/cache-vignettes/L62xH60/logofrif2-756e4.jpg' width='62' height='60' alt="" /></span></p> <p>Le laboratoire fait partie</p> <p>de la <a href="http://frif.fr/" class='spip_out' rel='external'>FRIF</a> <br class='autobr' />
(Fédération de Recherche Interactions Fondamentales)</p></div>
Dernières publicationshttp://www.lpthe.jussieu.fr/spip/spip.php?article176
http://www.lpthe.jussieu.fr/spip/spip.php?article1762008-04-24T15:38:49Ztext/htmlfrDamien BrémontA noter
<p>Dernières publications Complete two-loop QCD con... Sophia Borowka ; Sebastian Paßehr ; Georg Weiglein Physics perspectives with... L. Massacrier ; M. Anselmino ; R. Arnaldi ; S.J. Brodsky ; V. Chambert Probing Leptogenesis... E.J. Chun ; G. Cvetič ; P.S.B. Dev ; M. Drewes ; C.S. Fong A note on $\mathfrakgl_... S. Belliard ; N.A. Slavnov 1-Loop mass generation by... Bruno Machet</p>
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<a href="http://www.lpthe.jussieu.fr/spip/spip.php?rubrique16" rel="directory">A noter</a>
<div class='rss_texte'><p>Dernières publications<br/></p>
<ul><li><a href="https://hal.archives-ouvertes.fr/hal-01737825" onclick="window.open(this.href); return false;">Complete two-loop QCD con...</a><br/>
Sophia Borowka ; Sebastian Paßehr ; Georg Weiglein</li>
<li><a href="https://hal.archives-ouvertes.fr/hal-01730124" onclick="window.open(this.href); return false;">Physics perspectives with...</a><br/>
L. Massacrier ; M. Anselmino ; R. Arnaldi ; S.J. Brodsky ; V. Chambert</li>
<li><a href="https://hal.archives-ouvertes.fr/hal-01730080" onclick="window.open(this.href); return false;">Probing Leptogenesis...</a><br/>
E.J. Chun ; G. Cvetič ; P.S.B. Dev ; M. Drewes ; C.S. Fong</li>
<li><a href="https://hal.archives-ouvertes.fr/hal-01730057" onclick="window.open(this.href); return false;">A note on $\mathfrak<i>gl</i>_...</a><br/>
S. Belliard ; N.A. Slavnov</li>
<li><a href="http://hal.upmc.fr/hal-01723541" onclick="window.open(this.href); return false;">1-Loop mass generation by...</a><br/>
Bruno Machet</li>
</ul></div>